Houllier was discharged from hospital on Thursday night - just eight days after being admitted suffering from chest pains.
The Frenchman, who had major heart surgery while in charge of Liverpool, is almost certain not to return to Villa in an active role this season.
A significant question mark still remains over whether Houllier will be back at all given his medical history even though McAllister is positive that will eventually happen.
But the caretaker boss is adamant the wheels will still be in motion at Villa regarding dealing with attracting new signings, players leaving and those who are currently out of contract.
McAllister said: "All these things that from the outside we seem to have to deal with over the next few weeks, we've been looking through already. Of course, it would be better if Gerard was here, but everything is place for things to move on. Whether it be attracting new players, or players coming to the end of their contract, a lot of decisions have already been made."
Source: PA
Source: PA